The present invention relates to a small-size telescopic lens system with a brightness of 1:4, and an angle of view of .+-.6.degree..
Conventionally, in a telescopic lens system with a brightness of 1:4, with a system composite focal distance in the 200-mm class, the telescopic ratio, i.e., (the distance from the first lens surface in the system to the image surface)/(the composite focal distance of the entire system), is greater than 0.85.